A chemist uses a sample of 30 g of ethanol
(CH CH,OH) in an experiment.
How many moles of ethanol are used?
To calculate the number of moles of ethanol, we first need to find the molar mass of ethanol.
The molecular formula of ethanol is C2H5OH.
The molar mass of carbon (C) is 12.01 g/mol, hydrogen (H) is 1.01 g/mol, and oxygen (O) is 16.00 g/mol.
Molar mass of ethanol (C2H5OH) = (2 x 12.01) + (6 x 1.01) + 16.00
= 24.02 + 6.06 + 16.00
= 46.08 g/mol
Now, we can calculate the number of moles of ethanol:
Number of moles = Mass / Molar mass
Number of moles = 30 g / 46.08 g/mol ≈ 0.65 moles
Therefore, the chemist uses approximately 0.65 moles of ethanol in the experiment.